The field of growing plants using lamps is well know in the art and many systems have been proposed. Thus, it is extremely popular to use hydroponics to grow different types of plants. Generally, in such a growth system, a non-soil medium is utilised and the plant gathers the nutrients from a liquid to which the roots are exposed. There are many known types of hydroponic systems which need not be discussed in great detail herein.
One problem with hydroponic systems is that they consume a large area for a given yield. Generally, the plants grow from containers which usually lie in a horizontal plane and lights are suspended from above the plants and containers. A substantial amount of energy is required for these lights and accordingly, the use of hydroponics is relatively expensive in most situations. It will be understood that when natural light can be employed, the cost is naturally somewhat less although this implies the use of more energy for heating.
In order to overcome this problem, it has recently been proposed in the art to utilise a drum wherein the drum carries the non-soil medium in which the plant grows, and the drum rotates about a light source hereby maintaining a substantially constant distance between the plants and the light. The drum is rotated and there is provided a trough located at the bottom of the drum into which the plants or at least the root system, are immersed to thereby provide the required moisture and nutrients. One such arrangement is shown in published Canadian Patent Application 2,343,254 wherein the plants are placed in a pot and held by the rotating drum.
The advantage of such a system is that substantially less real estate is required for a given yield and a single light source can more efficiently serve to provide the desired light. As the given amount of light decreases exponentially with the distance between the light and the plants, such an arrangement becomes very efficient. However, one of the problems encountered with such an arrangement has been the relatively complex mechanical features and the problem of maintenance of the area. Thus, after the plants are immersed in the water, there tends to be a certain amount of dripping and a collector system must be provided in order to maintain a neat appearance.
Also, a problem which has been encountered in the prior art rotating drum systems is the maintenance of the correct light intensity. As aforementioned, the light intensity is an exponentially related to the distance between the plant and the light. As there must be sufficient room for the plants to grow, the light source must be a certain distance away from the plants. While this distance may be suitable when the plants are substantially full grown, the light intensity may be insufficient for the plants when they are very young.